Women and children crossing together illegally into the United States could be separated by U.S. authorities under a proposal being considered by the Department of Homeland Security, according to three government officials.

Part of the reason for the proposal is to deter mothers from migrating to the United States with their children, said the officials, who have been briefed on the proposal.

The policy shift would allow the government to keep parents in custody while they contest deportation or wait for asylum hearings. Children would be put into protective custody with the Department of Health and Human Services, in the “least restrictive setting” while until they can be taken into the care of a U.S. relative or state-sponsored guardian.

Currently, families contesting deportation or applying for asylum are generally released from detention quickly and allowed to remain in the United States until their cases are resolved. A federal appeals court ruling bars prolonged child detention.

President Donald Trump has called for ending so-called “catch and release,” in which migrants who cross illegally are freed to live in the United States while awaiting legal proceedings.